The larynx is an organ located in the human neck between the pharynx and the trachea. Nine cartilages make up the larynx including three single cartilages (epiglottic, thyroid and cricoid) and three paired cartilages (arytenoid, corniculate, and cuneiform). The larynx is further comprised of two flexible vocal folds that serve as the valve controlling the flow of air through the larynx for phonation or preventing the passage of solids and liquids to the trachea. The vocal folds are supported by the arytenoid cartilages. Muscles attached to the arytenoid cartilages control the degree of opening of the folds. Vocal fold length and tension can be controlled by rocking the thyroid cartilage forward and backward on the cricoid cartilage, by manipulating the tension of the muscles within the vocal folds, and by moving the arytenoids forward or backward.
Externally induced physical trauma can cause deformation of the structure of the larynx thereby interfering with the proper functioning of the vocal folds. There are also, for example, several disorders that can cause functioning of the vocal folds to degrade including:
Presbylarynx is a condition in which age-related atrophy of the soft tissues of the larynx results in weak voice and restricted vocal range and stamina.
Vocal cord paresis is weakness of one or both vocal folds that can greatly impact daily life.
Vocal cord plegia in which all voluntary movement of the vocal folds is lost.
Idiopathic laryngeal spasm.
Laryngomalacia that is a very common condition of infancy, in which the soft, immature cartilage of the upper larynx collapses inward during inhalation, causing airway obstruction.
Post radiation nerve and muscle injury.
Post-surgical nerve and muscle injury.
In some cases, the treatment of these conditions involves the placement of a mechanical support mechanism or stent to restore the required geometry to the structure of the larynx. For these modalities, the anchoring of the stent must be sufficiently secure to insure that the desired abduction force is stably applied. Some desirable features for such a stent include:                Biologically non-reactive—The stent should be of a construction and fabricated of materials that are biologically non-reactive.        Endoscopic Placement—The stent should be capable of endoscopic delivery with minimum potential for damaging to the contacted tissues.        Conformal—The stent should readily conform to the dimensions of the installation site and exert the required level of support force.        Atraumic—The stent should not migrate below nor cause degradation to the surface of the contacting tissue.        Repositionable—The stent should be repositionable by endoscopic methods even after an extended time period.        Removable—The stent should be endoscopically removable with minimal tissue damage.        